Miniature pneumatic device

ABSTRACT

A miniature pneumatic device includes a miniature fluid control device and a miniature valve device. The miniature fluid control device includes a gas inlet plate, a resonance plate, a piezoelectric actuator and a gas collecting plate. The length and width of the gas collecting plate are between 4 mm and 10 mm. A first chamber is formed between the resonance plate and the piezoelectric actuator. After a gas is fed into the gas inlet plate, the gas is transferred to the first chamber through the resonance plate and then transferred downwardly. Consequently, a pressure gradient is generated to continuously push the gas. The miniature valve device includes a valve film and a gas outlet plate. After the gas is transferred from the miniature fluid control device to the miniature valve device, the valve opening of the valve film is correspondingly opened or closed and the gas is transferred in one direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application of U.S.application Ser. No. 15/391,999 filed on Dec. 28, 2016, and claims thepriority to Taiwan Patent Application No. 105136558 filed on Nov. 10,2016, the entirety of which is hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a pneumatic device, and moreparticularly to a slim and silent miniature pneumatic device.

BACKGROUND OF THE INVENTION

With the advancement of science and technology, fluid transportationdevices used in many sectors such as pharmaceutical industries, computertechniques, printing industries or energy industries are developedtoward elaboration and miniaturization. The fluid transportation devicesare important components that are used in for example micro pumps, microatomizers, printheads or industrial printers. Therefore, it is importantto provide an improved structure of the fluid transportation device.

For example, in the pharmaceutical industries, pneumatic devices orpneumatic machines use motors or pressure valves to transfer gases.However, due to the volume limitations of the motors and the pressurevalves, the pneumatic devices or the pneumatic machines are bulky involume. In other words, the conventional pneumatic device fails to meetthe miniaturization requirement, and is not suitable to be installed inor cooperated with a portable equipment. Moreover, during operations ofthe motor or the pressure valve, annoying noise is readily generated.

Therefore, there is a need of providing a miniature pneumatic devicewith small, miniature, silent, portable and comfortable benefits inorder to eliminate the above drawbacks.

SUMMARY OF THE INVENTION

The present invention provides a miniature pneumatic device for use witha portable or wearable equipment or machine. The miniature pneumaticdevice is a combination of a miniature fluid control device and aminiature valve device. The miniature pneumatic device of the presentinvention is small, slim, portable and silent. Consequently, thedrawbacks of the conventional pneumatic device are overcome.

In accordance with an aspect of the present invention, a miniaturepneumatic device is provided. The miniature pneumatic device includes aminiature fluid control device and a miniature valve device. Theminiature fluid control device includes a gas inlet plate, a resonanceplate, a piezoelectric actuator and a gas collecting plate. Theresonance plate has a central aperture. A length of the gas collectingplate is in a range between 4 mm and 10 mm. A width of the gascollecting plate is in a range between 4 mm and 10 mm. A length/widthratio of the gas collecting plate is in a range between 0.4 and 2.5. Thegas inlet plate, the resonance plate, the piezoelectric actuator and thegas collecting plate are stacked on each other sequentially. A gap isformed between the resonance plate and the piezoelectric actuator todefine a first chamber. When the piezoelectric actuator is actuated, agas is fed into the miniature fluid control device through the gas inletplate, transferred through the resonance plate, introduced into thefirst chamber, and further transferred. The miniature valve deviceincludes a valve film and a gas outlet plate. The gas collecting plate,the valve film and the gas outlet plate are combined together. The valvefilm has a valve opening, and a length and a width of the gas outletplate are identical to those of the gas collecting plate. After the gasis transferred from the miniature fluid control device to the miniaturevalve device, a pressure-collecting operation or a pressure-releasingoperation is selectively performed.

The above contents of the present invention will become more readilyapparent to those ordinarily skilled in the art after reviewing thefollowing detailed description and accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic exploded view illustrating a miniature pneumaticdevice according to an embodiment of the present invention and takenalong a first viewpoint;

FIG. 1B is a schematic assembled view illustrating the miniaturepneumatic device of FIG. 1A;

FIG. 2A is a schematic exploded view illustrating the miniaturepneumatic device according to the embodiment of the present inventionand taken along a second viewpoint;

FIG. 2B is a schematic assembled view illustrating the miniaturepneumatic device of FIG. 2A;

FIG. 3A is a schematic perspective view illustrating the piezoelectricactuator of the miniature pneumatic device of FIG. 1A and taken alongthe front side;

FIG. 3B is a schematic perspective view illustrating the piezoelectricactuator of the miniature pneumatic device of FIG. 1A and taken alongthe rear side;

FIG. 3C is a schematic cross-sectional view illustrating thepiezoelectric actuator of the miniature pneumatic device of FIG. 1A;

FIGS. 4A to 4C schematically illustrate various exemplary piezoelectricactuator used in the miniature pneumatic device of the presentinvention;

FIGS. 5A to 5E schematically illustrate the actions of the miniaturefluid control device of the miniature pneumatic device of FIG. 1A;

FIG. 6A schematically illustrate a gas-collecting operation of theminiature valve device of the miniature pneumatic device of FIG. 1A;

FIG. 6B schematically illustrate a gas-releasing operation of theminiature valve device of the miniature pneumatic device of FIG. 1A;

FIGS. 7A to 7E schematically illustrate a gas-collecting operation ofthe miniature pneumatic device of FIG. 1A; and

FIG. 8 schematically illustrate the gas-releasing actions or thepressure-reducing actions of the miniature pneumatic device of FIG. 1A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will now be described more specifically withreference to the following embodiments. It is to be noted that thefollowing descriptions of preferred embodiments of this invention arepresented herein for purpose of illustration and description only. It isnot intended to be exhaustive or to be limited to the precise formdisclosed.

The present invention provides a miniature pneumatic device. Theminiature pneumatic device may be used in many sectors such aspharmaceutical industries, energy industries, computer techniques orprinting industries for transporting gases.

Please refer to FIGS. 1A, 1B, 2A, 2B and 7A to 7E. FIG. 1A is aschematic exploded view illustrating a miniature pneumatic deviceaccording to an embodiment of the present invention and taken along afirst viewpoint. FIG. 1B is a schematic assembled view illustrating theminiature pneumatic device of FIG. 1A. FIG. 2A is a schematic explodedview illustrating the miniature pneumatic device according to theembodiment of the present invention and taken along a second viewpoint.FIG. 2B is a schematic assembled view illustrating the miniaturepneumatic device of FIG. 2A. FIGS. 7A to 7E schematically illustrate agas-collecting operation of the miniature pneumatic device of FIG. 1A.

As shown in FIGS. 1A and 2A, the miniature pneumatic device 1 comprisesa miniature fluid control device 1A and a miniature valve device 1B. Inthis embodiment, the miniature fluid control device 1A comprises ahousing 1 a, a piezoelectric actuator 13, a first insulation plate 141,a conducting plate 15 and a second insulation plate 142. The housing 1 acomprises a gas collecting plate 16 and a base 10. The base 10 iscomposed of a gas inlet plate 11 and a resonance plate 12. Thepiezoelectric actuator 13 is aligned with the resonance plate 12. Thegas inlet plate 11, the resonance plate 12, the piezoelectric actuator13, the first insulation plate 141, the conducting plate 15, the secondinsulation plate 142 and the gas collecting plate 16 are stacked on eachother sequentially to be assembled while an outward surface of the gasinlet plate 11 is towards an input side. Moreover, the piezoelectricactuator 13 comprises a suspension plate 130, an outer frame 131, atleast one bracket 132 and a piezoelectric ceramic plate 133. In thisembodiment, the miniature valve device 1B comprises a valve film 17 anda gas outlet plate 18.

As shown in FIG. 1A, the gas collecting plate 16 may comprise a bottomplate and a sidewall 168 protruding from the edges of the bottom plate.The gas collecting plate 16 may have a length and a width both in therange between 4 mm and 10 mm, while the length/width ratio of the gascollecting plate 16 is in the range between 0.4 and 2.5. Alternatively,the length and the width of the gas collecting plate 16 are both in therange between 6 mm and 8 mm, while the length/width ratio of the gascollecting plate 16 is in the range between 0.75 and 1.33. Preferably,the length and the width of the gas collecting plate 16 are both 6 mm.

The bottom plate and the sidewall 168 collaboratively define anaccommodation space 16 a where the piezoelectric actuator 13 is disposedwithin. The structure of the miniature pneumatic device 1 in assembledstate, taken from the front side, is shown in FIG. 1B and FIGS. 7A to7E. As the miniature fluid control device 1A and the miniature valvedevice 1B are combined together, the valve film 17 and the gas outletplate 18 of the miniature valve device 1B are stacked on each other andpositioned on the bottom side of the gas collecting plate 16 of theminiature fluid control device 1A. Please refer to FIG. 1A and FIG. 2B,the gas outlet plate 18 has a pressure-releasing perforation 181 and anoutlet structure 19. The outlet structure 19 is adapted to be incommunication with an inner space of a target equipment (not shown), andthe pressure-releasing perforation 181 is adapted to discharge the gasinside the miniature valve device 1B. As so, the gas pressure of theinner space of the target equipment can be released.

The miniature pneumatic device 1 in assembled state allows a gas to befed into the miniature fluid control device 1A through at least oneinlet 110 of the gas inlet plate 11 from the input side. Thepiezoelectric actuator 13 is operable to be activated, and in responseof the actions of the piezoelectric actuator 13, the gas is transferreddownwardly through plural pressure chambers (not shown) to the miniaturevalve device 1B. In the miniature valve device 1B, the gas istransferred in one direction, being discharged from the outlet structure19 and flows into the inner space of the target equipment (not shown).As a result, the pressure of the gas in the inner space of the targetequipment is accumulated.

Please refer to FIGS. 1A and 2A again. The gas inlet plate 11 of theminiature fluid control device 1A comprises a first surface 11 b, asecond surface 11 a and the at least one inlet 110. In this embodiment,the gas inlet plate 11 has four inlets 110. The inlets 110 run throughthe first surface 11 b and the second surface 11 a of the gas inletplate 11, and the second surface 11 a is towards exterior of theminiature pneumatic device 1 where is defined as the input side. Inresponse to the action of the atmospheric pressure, the gas isintroduced into the miniature fluid control device 1A through the inlets110. As shown in FIG. 2A, at least one convergence channel 112 is formedon the first surface 11 b of the gas inlet plate 11, and is incommunication with the at least one inlet 110 of the gas inlet plate 11.Moreover, a central cavity 111 is formed on the first surface 11 b ofthe gas inlet plate 11 and located at the intersection of the fourconvergence channels 112 that forming a convergence chamber fortemporarily storing the gas. The central cavity 111 is in communicationwith all of the convergence channels 112, such that the gas entered bythe inlets 110 would be introduced into the at least one convergencechannel 112 and is guided to the central cavity 111. In this embodiment,the at least one inlet 110, the at least one convergence channel 112 andthe central cavity 111 of the gas inlet plate 11 are integrally formed.

Preferably but not exclusively, the gas inlet plate 11 is made ofstainless steel. The thickness of the gas inlet plate 11 is in the rangebetween 0.3 mm and 0.5 mm, and preferably 0.4 mm. In some embodiments,the depth of the convergence chamber defined by the central cavity 111,is equal to the depth of the at least one convergence channel, both ofwhich are preferably in the range between 0.15 mm and 0.25 mm. Theresonance plate 12 is made of a flexible material, which is preferablybut not exclusively copper. The resonance plate 12 further has a centralaperture 120 corresponding to the central cavity 111 of the gas inletplate 11 that providing the gas for flowing through. The thickness ofthe resonance plate 12 is in the range between 0.02 mm and 0.07 mm, andpreferably 0.04 mm.

FIG. 3A is a schematic perspective view illustrating the piezoelectricactuator of the miniature pneumatic device of FIG. 1A and taken alongthe front side. FIG. 3B is a schematic perspective view illustrating thepiezoelectric actuator of the miniature pneumatic device of FIG. 1A andtaken along the rear side. FIG. 3C is a schematic cross-sectional viewillustrating the piezoelectric actuator of the miniature pneumaticdevice of FIG. 1A. As shown in FIGS. 3A, 3B and 3C, the piezoelectricactuator 13 comprises the suspension plate 130, the outer frame 131, theat least one bracket 132, and the piezoelectric ceramic plate 133. Thepiezoelectric ceramic plate 133 is attached on a first surface 130 b ofthe suspension plate 130. In response to an applied voltage, thepiezoelectric ceramic plate 133 would be subjected to a curvy vibration.The suspension plate 130 comprises a middle portion 130 d and aperiphery portion 130 e. When the piezoelectric ceramic plate 133 issubjected to the curvy vibration, the suspension plate 130 is alsosubjected to the curvy vibration and vibrates from the middle portion130 d to the periphery portion 130 e. The at least one bracket 132 isconnected between the suspension plate 130 and the outer frame 131,while two ends of the bracket 132 are connected with the outer frame 131and the suspension plate 130 respectively that the bracket 131 canelastically support the suspension plate 130. At least one vacant space135 is formed between the bracket 132, the suspension plate 130 and theouter frame 131 for allowing the gas to go through. The type of thesuspension plate 130 and the outer frame 131 and the type and the numberof the at least one bracket 132 may be varied according to the practicalrequirements. Moreover, a conducting pin 134 is protruding outwardlyfrom the outer frame 131 so as to be electrically connected with anexternal circuit (not shown).

In this embodiment, the suspension plate 130 has a bulge 130 c thatmakes the suspension plate 130 a stepped structure. The bulge 130 c isformed on a second surface 130 a of the suspension plate 130, whereinthe second surface 130 a is opposing to the first surface 130 b. Thebulge 130 c may be a circular convex structure, the thickness of whichis in the range between 0.02 mm and 0.08 mm, and preferably 0.03 mm.Preferably but not exclusively, the diameter of the bulge 130 c is in arange between 1.1 mm and 2.4 mm. As shown in FIGS. 3A and 3C, a topsurface of the bulge 130 c of the suspension plate 130 is coplanar witha second surface 131 a of the outer frame 131, while the second surface130 a of the suspension plate 130 is coplanar with a second surface 132a of the bracket 132. Moreover, there is a drop of specified amount fromthe bulge 130 c of the suspension plate 130 (or the second surface 131 aof the outer frame 131) to the second surface 130 a of the suspensionplate 130 (or the second surface 132 a of the bracket 132). As shown inFIGS. 3B and 3C, a first surface 130 b of the suspension plate 130, afirst surface 131 b of the outer frame 131 and a first surface 132 b ofthe bracket 132 are coplanar with each other. The piezoelectric ceramicplate 133 is attached on the first surface 130 b of the suspension plate130. The suspension plate 130 may be a square plate structure with twoflat surfaces but the type of the suspension plate 130 may be variedaccording to the practical requirements. In this embodiment, thesuspension plate 130, the at least bracket 132 and the outer frame 131are integrally formed and produced by using a metal plate (e.g., astainless steel plate). The thickness of the suspension plate 130 is inthe range between 0.1 mm and 0.3 mm, and preferably 0.2 mm. The lengthof the suspension plate 130 is in the range between 2 mm and 4.5 mm, andpreferably in the range between 2.5 mm and 3.5 mm. The width of thesuspension plate 130 is in the range between 2 mm and 4.5 mm, andpreferably in the range between 2.5 mm and 3.5 mm. The thickness of theouter frame 131 is in the range between 0.1 mm and 0.4 mm, andpreferably 0.3 mm.

The piezoelectric ceramic plate 133 has the same shape with thesuspension plate 130 but in smaller size, which means the longest sideof the piezoelectric ceramic plate 133 is always equal to or shorterthan the longest side of the suspension plate 130. As the suspensionplate 130 has a square shape in this embodiment, the piezoelectricceramic plate 133 also has a square shape. The thickness of thepiezoelectric ceramic plate 133 is in the range between 0.05 mm and 0.3mm, and preferably 0.10 mm. The length of a side of the piezoelectricceramic plate 133 is equal to or less than the length of a side of thesuspension plate 130. Meanwhile, the length of the side of thepiezoelectric ceramic plate 133 is in the range between 2 mm and 4.5 mm,and preferably in the range between 2.5 mm and 3.5 mm. In some otherembodiments, the suspension plate 130 and the piezoelectric ceramicplate 133 may have a rectangular shape, and the width and the length ofthe rectangular shape is in the range between 2 mm and 4.5 mm, andpreferably in the range between 2.5 mm and 3.5 mm. Moreover, thelength/width ratio of the piezoelectric ceramic plate 133 is in therange between 0.44 and 2.25.

Preferably, the piezoelectric actuator 13 used in the miniaturepneumatic device 1 of the present invention is a square piezoelectricactuator. The reason is that the square piezoelectric actuator is morepower-saving in comparison with the circular one. The comparison betweenthe consumed power and the operating frequency for the piezoelectricactuators of different types and sizes is shown in Table 1.

TABLE 1 Type of piezoelectric actuator Operating frequency Consumedpower Square (side length: 10 mm) 18 kHz 1.1 W Circular (diameter: 10mm) 28 kHz 1.5 W Square (side length: 9 mm) 22 kHz 1.3 W Circular(diameter: 9 mm) 34 kHz   2 W Square (side length: 8 mm) 27 kHz 1.5 WCircular (diameter: 8 mm) 42 kHz 2.5 W

From the results of Table 1, it is found that the square piezoelectricactuator is more power-saving than the circular piezoelectric actuatorof same size. That is, the piezoelectric actuator with the squaresuspension plate consumes less power. It is generally known that theconsumed power of the capacitive load at the resonance frequency ispositively related to the resonance frequency. Since the resonancefrequency of the square piezoelectric actuator 13 is obviously lowerthan that of the circular piezoelectric actuator of same size, theconsumed power of the square suspension plate is lower. Taking advantageof the power-saving square piezoelectric actuator 13, the miniaturepneumatic device 1 would be suitably used in the wearable device.

FIGS. 4A, 4B and 4C schematically illustrate various exemplarypiezoelectric actuator used in the miniature pneumatic device of thepresent invention. As shown in the drawings, the suspension plate 130,the outer frame 131 and the at least one bracket 132 of thepiezoelectric actuator 13 have various types.

FIG. 4A schematically illustrates the types (a)˜(l) of the piezoelectricactuator. In the type (a), the outer frame a1 and the suspension platea0 are square, the outer frame a1 and the suspension plate a0 areconnected with each other through eight brackets a2, each two of whichare disposed by one side of the square suspension plate a0. Severalvacant spaces a3 are formed between the brackets a2, the suspensionplate a0 and the outer frame a1 for allowing the gas to go through. Inthe type (i), the outer frame it and the suspension plate i0 are alsosquare, but the outer frame it and the suspension plate i0 are connectedwith each other through merely two brackets i2. In addition, the outerframe it and the suspension plate i0 in each of the types (b)˜(h) arealso square. In each of the types (j)˜(l), the suspension plate iscircular, and the outer frame has a square with arc-shaped corners. Forexample, in the type (j), the suspension plate j0 is circular, and theouter frame has a square with arc-shaped corners. As mentioned above,the suspension plate 130 has a square or circular shape, and thepiezoelectric ceramic plate 133 is attached on the first surface 130 bof the suspension plate 130 also has the square or circular shape.

FIG. 4B schematically illustrates the types (m)˜(r) of the piezoelectricactuator. In these types (m)˜(r), the suspension plate 130 and the outerframe 131 are square. In the type (m), the outer frame m1 and thesuspension plate m0 are square, the outer frame m1 and the suspensionplate m0 are connected with each other through four brackets m2, each ofwhich is disposed by one side of the suspension plate m0. Meanwhile, avacant space m3 is formed between the brackets m2, the suspension platem0 and the outer frame m1. The bracket m2 has two ends m2′ and m2″respectively connected with the outer frame m1 and the suspension platem0. The two ends m2′ and m2″ are opposed to each other and arrangedalong the same horizontal line.

In the type (n), the outer frame n1 and the suspension plate n0 are alsoconnected with each other through four brackets n2, and a vacant spacen3 is formed between the brackets n2, the suspension plate n0 and theouter frame n1. Nonetheless, the two ends n2′ and n2″ of the bracket n2,which are respectively connected with the outer frame n1 and thesuspension plate n0, are not arranged along the same horizontal line.Instead, the two ends n2′ and n2″ are inclined at 0˜45 degrees withrespect to the horizontal line.

In the type (o), the outer frame of and the suspension plate o0 aresquare, the outer frame o1 and the suspension plate o0 are connectedwith each other through four brackets o2 in circular profiles, and avacant space o3 is formed between each two of the brackets o2, thesuspension plate o0 and the outer frame o1. The bracket o2 includes aconnecting part and two ends o2′ and o2″. The end o2′ of the bracket o2is connected with the outer frame o1. The end o2″ of the bracket o2 isconnected with the suspension plate o0. The two ends o2′ and o2″ areopposed to each other and arranged along the same horizontal line.

In the type (p), the outer frame p1 and the suspension plate p0 aresquare, the outer frame p1 and the suspension plate p0 are connectedwith each other through four brackets p2, and a vacant space p3 isformed between each two of the brackets p2, the suspension plate p0 andthe outer frame p1. The bracket p2 includes a first connecting part p20,an intermediate part p21 and a second connecting part p22. Theintermediate part p21 is formed in the vacant space p3 and in parallelwith the outer frame p1 and the suspension plate p0. The firstconnecting part p20 is arranged between the intermediate part p21 andthe suspension plate p0. The second connecting part p22 is arrangedbetween the intermediate part p21 and the outer frame p1. The firstconnecting part p20 and the second connecting part p22 are opposed toeach other and arranged along the same horizontal line.

More specifically, the intermediate part p21 is a bar perpendicular toboth the first connecting part p20 and the second connecting part p22,which makes the bracket p2 in the shape of a cross. Thus, the wholestructure of the bracket p2 is strengthened, which is beneficial forvibration of the suspension plate p0 in a fixed direction. Meanwhile,the bracket p2 can be made of a material with a lesser rigidity, andtherefore increases vibration frequency of the suspension plate p0. As aresult, the gas pressure output efficiency could be improved.

In the type (q), the outer frame q1, the suspension plate q0, thebracket q2 and the vacant space q3 are similar to those of the type (m)and the type (o). Each side of the suspension plate q0 is connected withthe corresponding side of the outer frame q1 through two connectingparts q2. The two ends q2′ and q2″ of each connecting part q2 areopposed to each other and arranged along the same horizontal line. Inthe type (r), the outer frame r1, the suspension plate r0, the bracketr2 and the vacant space r3 are similar to those of the aboveembodiments. However, the bracket r2 is a V-shaped connecting part. Thatis, the bracket r2 is connected with the outer frame r1 and thesuspension plate r0 at an inclined angle 0˜45 degrees. An end r2″ of thebracket r2 is connected with the suspension plate r0, and two ends r2′of the bracket r2 are connected with the outer frame r1. That is, theends b2′ and b2″ are not arranged along the same horizontal line.

FIG. 4C schematically illustrates the types (s)˜(x) of the piezoelectricactuator. The structures of the types (s)˜(x) are similar to those ofthe types (m)˜(r), respectively. However, in the types (s)˜(x), thesuspension plate 130 of the piezoelectric actuator 13 has a bulge 130 c.The bulges 130 c in the types (s)˜(x) are indicated as s4, t4, u4, v4,w4 and x4, respectively. Regarding the types (m)˜(r) and the types(s)˜(x) of the piezoelectric actuator, the suspension plate 130 and theouter frame 131 are square for achieving power-saving efficacy, and boththe stepped structure with bulge and the flat structure with two flatsurfaces are in the scope of the present invention. Meanwhile, thenumber of the brackets 132 between the outer frame 131 and thesuspension plate 130 may be varied according to the practicalrequirements. The suspension plate 130, the outer frame 131 and the atleast one bracket 132 may be integrally formed with each other andproduced by but not limited to a conventional machining process, aphotolithography and etching process, a laser machining process, anelectroforming process, an electric discharge machining process and soon.

Please refer to FIGS. 1A and 2A again. The miniature fluid controldevice 1A further comprises the first insulation plate 141, theconducting plate 15 and the second insulation plate 142. The firstinsulation plate 141, the conducting plate 15 and the second insulationplate 142 are stacked on each other sequentially and located under thepiezoelectric actuator 13. The profiles of the first insulation plate141, the conducting plate 15 and the second insulation plate 142substantially match the profile of the outer frame 131 of thepiezoelectric actuator 13. The first insulation plate 141 and the secondinsulation plate 142 are made of an insulating material (e.g. a plasticmaterial) for providing insulating efficacy. The conducting plate 15 ismade of an electrically conductive material (e.g. a metallic material)for providing electrically conducting efficacy. Moreover, the conductingplate 15 has a conducting pin 151 so as to be electrically connectedwith an external circuit (not shown).

FIGS. 5A to 5E schematically illustrate the actions of the miniaturefluid control device of the miniature pneumatic device of FIG. 1A. Asshown in FIG. 5A, the gas inlet plate 11, the resonance plate 12, thepiezoelectric actuator 13, the first insulation plate 141, theconducting plate 15 and the second insulation plate 142 of the miniaturefluid control device 1A are stacked on each other sequentially.Moreover, there is a gap g0 between the resonance plate 12 and the outerframe 131 of the piezoelectric actuator 13, which is formed andmaintained by a filler (e.g. a conductive adhesive) inserted therein inthis embodiment. The gap g0 ensures the proper distance between theresonance plate 12 and the bulge 130 c of the suspension plate 130, sothat the contact interference is reduced and the generated noise islargely reduced. In some other embodiments, the outer frame 131 isproduced to be at a level higher than the piezoelectric actuator 13, sothat the gap is formed between the resonance plate 12 and thepiezoelectric actuator 13.

Please refer to FIGS. 5A to 5E again. A convergence chamber is definedby the resonance plate 12 and the central cavity 111 of the gas inletplate 11 collaboratively for converging the gas. A first chamber 121 isformed between the resonance plate 12 and the piezoelectric actuator 13,and is in communication with the convergence chamber through the centralaperture 120 of the resonance plate 12. Meanwhile, the peripheralregions of the first chamber 121 are in communication with theunderlying miniature valve device 1B through the vacant spaces 135 ofthe piezoelectric actuator 13.

Please refer to FIG. 5B. When the miniature fluid control device 1A ofthe miniature pneumatic device 1 is enabled, the piezoelectric actuator13 is actuated in response to an applied voltage. Consequently, thepiezoelectric actuator 13 vibrates along a vertical direction in areciprocating manner, while the brackets 132 are served as the fulcrums.The resonance plate 12 except for the part of it fixed on the gas inletplate 11 is hereinafter referred as a movable part 12 a, while the restis referred as a fixed part 12 b. Since the resonance plate 12 is lightand thin, the movable part 12 a vibrates along with the piezoelectricactuator 13 because of the resonance of the piezoelectric actuator 13.In other words, the movable part 12 a is reciprocated and subjected to acurvy deformation.

As shown in FIG. 5C, during the vibration of the movable part 12 a ofthe resonance plate 12, the movable part 12 a moves down till beingcontacted with the bulge 130 c of the suspension plate 130. In themeantime, the volume of the first chamber 121 is shrunken and a middlespace which was communicating with the convergence chamber is closed. Asa result, the pressure gradient occurs to push the gas in the firstchamber 121 moving toward peripheral regions of the first chamber 121and flowing downwardly through the vacant spaces 135 of thepiezoelectric actuator 13.

Please refer to FIG. 5D, which illustrates consecutive action followingthe action in FIG. 5C. The movable part 12 a has returned its originalposition as the piezoelectric actuator 13 has ascended at a vibrationdisplacement d to an upward position. Consequently, the volume of thefirst chamber 121 is consecutively shrunken that generating pressuregradient which makes the gas in the first chamber 121 continuouslypushed toward peripheral regions and results in an exterior gascontinuously fed into the inlets 110 of the gas inlet plate 11 andtransferred to the central cavity 111.

Then, as shown in FIG. 5E, the resonance plate 12 moves upwardly, whichis caused by the resonance of the upward motion of the piezoelectricactuator 13. That is, the movable part 12 a of the resonance plate 12 isreturned to its original position. Under this circumstance, the volumeof the first chamber 121 expends, which results in suction applied tothe gas in the central cavity 111. The gas in the central cavity 111 istransferred to the first chamber 121 through the central aperture 120 ofthe resonance plate 12, then transferred downwardly through the vacantspaces 135 of the piezoelectric actuator 13, exiting from the miniaturefluid control device 1A.

From the above description, please note the gap g0 between the resonanceplate 12 and the piezoelectric actuator 13 providing space for vibrationof the resonance plate 12. That is, the thickness of the gap g0 affectsthe amplitude of vibration of the resonance plate 12. A difference xbetween the gap g0 and the vibration displacement d of the piezoelectricactuator 13 is given by a formula: x=g0−d. A series of tests about themaximum output pressure of the miniature pneumatic device 1corresponding to different values of x are performed. In case that x≤0μm, the miniature pneumatic device 1 generates noise. In case that x=1μm˜5 μm, the maximum output pressure of the miniature pneumatic device 1reaches 350 mmHg. In case that x=5 μm˜10 μm, the maximum output pressureof the miniature pneumatic device 1 is 250 mmHg. In case that x=10 μm˜15μm, the maximum output pressure of the miniature pneumatic device 1 is150 mmHg. The relationships between the difference x and the maximumoutput pressure are listed in Table 2 below. The data shown in Table 2are obtained when the operating voltage is in the range between ±10V and±20V. A pressure gradient is generated in the fluid channels of theminiature fluid control device 1A to facilitate the gas to flow at ahigh speed. Moreover, since there is an impedance difference between thefeeding direction and the exiting direction, the gas can be transmittedfrom the input side to the inner space of the target equipment. Even ifthe inner space of the target equipment has a certain gas pressure, theminiature fluid control device 1A still has the capability of pushingout the gas as well as achieving the silent efficacy.

TABLE 2 Test X Maximum output pressure 1 x = 1 μm~5 μm 350 mmHg 2 x = 5μm~10 μm 250 mmHg 3 x = 10 μm~15 μm 150 mmHg

In some embodiments, the vibration frequency of the resonance plate 12along the vertical direction in the reciprocating manner is identical tothe vibration frequency of the piezoelectric actuator 13. That is, theresonance plate 12 and the piezoelectric actuator 13 are synchronouslyvibrated along the upward direction or the downward direction. It isnoted that numerous modifications and alterations of the actions of theminiature fluid control device 1A may be made while retaining theteachings of the invention.

Please refer to FIGS. 1A, 2A, 6A and 6B. FIG. 6A schematicallyillustrate a gas-collecting operation of the miniature valve device ofthe miniature pneumatic device of FIG. 1A. FIG. 6B schematicallyillustrate a gas-releasing operation of the miniature valve device ofthe miniature pneumatic device of FIG. 1A. As shown in FIGS. 1A and 6A,the valve film 17 and the gas outlet plate 18 of the miniature valvedevice 1B are stacked on each other sequentially. Moreover, theminiature valve device 1B cooperates with the gas collecting plate 16 ofthe miniature fluid control device 1A.

In this embodiment, the gas collecting plate 16 comprises a firstsurface 160 and a second surface 161 (also referred as a fiducialsurface). The first surface 160 of the gas collecting plate 16 isconcaved to define a gas-collecting chamber 162 which accommodates thepiezoelectric actuator 13. The gas that is transferred downwardly by theminiature fluid control device 1A is temporarily accumulated in thegas-collecting chamber 162. The gas collecting plate 16 has a firstperforation 163 and a second perforation 164. A first end of the firstperforation 163 and a first end of the second perforation 164 arerespectively in communication with the gas-collecting chamber 162. Asecond end of the first perforation 163 and a second end of the secondperforation 164 are in communication with a first pressure-releasingchamber 165 and a first outlet chamber 166, which are formed on thesecond surface 161 of the gas collecting plate 16. Moreover, the gascollecting plate 16 has a raised structure 167 corresponding to thefirst outlet chamber 166. For example, the raised structure 167 includesbut is not limited to a cylindrical post. The raised structure 167 islocated at a level higher than the second surface 161 of the gascollecting plate 16. Moreover, a thickness of the raised structure 167is in a range between 0.1 mm and 0.55 mm, and preferably 0.2 mm.

The length and the width of the gas outlet plate 18 are identical tothose of the gas collecting plate 16. The gas outlet plate 18 comprisesa pressure-releasing perforation 181, an outlet perforation 182, a firstsurface 180 (also referred as a fiducial surface) and a second surface187. The pressure-releasing perforation 181 and the outlet perforation182 run through the first surface 180 and the second surface 187. Thefirst surface 180 of the gas outlet plate 18 is concaved to define asecond pressure-releasing chamber 183 and a second outlet chamber 184.The pressure-releasing perforation 181 is located at a center of thesecond pressure-releasing chamber 183. The outlet perforation 182 is incommunication with the second outlet chamber 184. Moreover, the gasoutlet plate 18 further comprises a communication channel 185 betweenthe second pressure-releasing chamber 183 and the second outlet chamber184 for allowing the gas to go through. A first end of the outletperforation 182 is in communication with the second outlet chamber 184.A second end of the outlet perforation 182 is in communication with anoutlet structure 19 to gain access to the inner space of the targetequipment. The outlet structure 19 is in connected with the targetequipment (not shown). The equipment is for example but not limited to agas-pressure driving equipment.

The valve film 17 comprises a valve opening 170 and plural positioningopenings 171 (see FIG. 1A). The thickness of the valve film 17 is in therange between 0.1 mm and 0.3 mm, and preferably 0.2 mm.

After the gas collecting plate 16, the valve film 17 and the gas outletplate 18 are combined together, the pressure-releasing perforation 181of the gas outlet plate 18 is aligned with the first perforation 163 ofthe gas collecting plate 16, the second pressure-releasing chamber 183of the gas outlet plate 18 is aligned with the first pressure-releasingchamber 165 of the gas collecting plate 16, and the second outletchamber 184 of the gas outlet plate 18 is aligned with the first outletchamber 166 of the gas collecting plate 16. The valve film 17 isarranged between the gas collecting plate 16 and the gas outlet plate 18for blocking the communication between the first pressure-releasingchamber 165 and the second pressure-releasing chamber 183. The valveopening 170 of the valve film 17 is arranged between the secondperforation 164 and the outlet perforation 182. Moreover, the valveopening 170 of the valve film 17 is aligned with the raised structure167 corresponding to the first outlet chamber 166 of the gas collectingplate 16. Due to such arrangement of the single valve opening 170, thegas can be transferred through the miniature valve device 1B in onedirection in response to the pressure difference.

In this embodiment, the gas outlet plate 18 has the convex structure 181a beside a first end of the pressure-releasing perforation 181.Preferably but not exclusively, the convex structure 181 a is acylindrical post. The thickness of the convex structure 181 a is in therange between 0.1 mm and 0.55 mm, and preferably 0.2 mm. The top surfaceof the convex structure 181 a is located at a level higher than thefirst surface 180 of the gas outlet plate 18. Consequently, thepressure-releasing perforation 181 can be quickly contacted with andclosed by the valve film 17. Moreover, the convex structure 181 a canprovide a pre-force against the valve film 17 to achieve a good sealingeffect. In this embodiment, the gas outlet plate 18 further comprises aposition-limiting structure 188. The thickness of the position-limitingstructure 188 is 0.2 mm. The position-limiting structure 188 is disposedwithin the second pressure-releasing chamber 183. Preferably but notexclusively, the position-limiting structure 188 is a ring-shapedstructure. While the gas-collecting operation of the miniature valvedevice 1B is performed, the position-limiting structure 188 can assistin supporting the valve film 17 and avoid collapse of the valve film 17.Consequently, the valve film 17 can be opened or closed more quickly.

Hereinafter, the gas-collecting operation of the miniature valve device1B will be illustrated with reference to FIG. 6A. In case that the gasfrom the miniature fluid control device 1A is being transferreddownwardly to the miniature valve device 1B, or the ambient air pressureis higher than the inner pressure of the target equipment which is incommunication with the outlet structure 19, the gas will be transferredfrom the miniature fluid control device 1A to the gas-collecting chamber162 of the miniature valve device 1B. Then, the gas is transferreddownwardly to the first pressure-releasing chamber 165 and the firstoutlet chamber 166 through the first perforation 163 and the secondperforation 164. In response to the downward gas, the flexible valvefilm 17 is subjected to a downward curvy deformation. Consequently, thevolume of the first pressure-releasing chamber 165 is expanded, and thevalve film 17 is in close contact with the first end of thepressure-releasing perforation 181 corresponding to the firstperforation 163. Under this circumstance, the pressure-releasingperforation 181 of the gas outlet plate 18 is closed, and thus the gaswithin the second pressure-releasing chamber 183 is not leaked out fromthe pressure-releasing perforation 181. In this embodiment, the gasoutlet plate 18 has the convex structure 181 a beside of the first endof the pressure-releasing perforation 181. Due to the arrangement of theconvex structure 181 a, the pressure-releasing perforation 181 can bequickly closed by the valve film 17. Moreover, the convex structure 181a can provide a pre-force to achieve a good sealing effect. Theposition-limiting structure 188 is arranged around thepressure-releasing perforation 181 to assist in supporting the valvefilm 17 and avoid collapse of the valve film 17. On the other hand, thegas is transferred downwardly to the first outlet chamber 166 throughthe second perforation 164. In response to the downward gas, the valvefilm 17 corresponding to the first outlet chamber 166 is also subjectedto the downward curvy deformation. Consequently, the valve opening 170of the valve membrane 17 is correspondingly opened to the downward side.Under this circumstance, the gas is transferred from the first outletchamber 166 to the second outlet chamber 184 through the valve opening170. Then, the gas is transferred to the outlet structure 19 through theoutlet perforation 182 and then transferred to the inner space of thetarget equipment which is in communication with the outlet structure 19.Consequently, the purpose of collecting the gas pressure is achieved.

Hereinafter, the gas-releasing operation of the miniature valve device1B will be illustrated with reference to FIG. 6B. For performing thegas-releasing operation, the user may adjust the amount of the gas to befed into the miniature fluid control device 1A, so that the gas is nolonger transferred to the gas-collecting chamber 162. Alternatively, incase that the inner pressure of the target equipment which is incommunication with the outlet structure 19 is higher than the ambientair pressure, which means the gas pressure of the inner space of thetarget equipment is greater than the gas pressure of the input side, thegas-releasing operation may be performed. Under this circumstance, thegas is transferred from the outlet structure 19 to the second outletchamber 184 through the outlet perforation 182. Consequently, the volumeof the second outlet chamber 184 is expanded, and the flexible valvefilm 17 corresponding to the second outlet chamber 184 is subjected tothe upward curvy deformation. In addition, the valve film 17 is in closecontact with the gas collecting plate 16. Consequently, the valveopening 170 of the valve film 17 is closed by the gas collecting plate16. Moreover, the gas collecting plate 16 has the raised structure 167corresponding to the first outlet chamber 166. Due to the arrangement ofthe raised structure 167, the flexible valve film 17 can be bentupwardly more quickly. Moreover, the raised structure 167 can provide apre-force to achieve a good sealing effect of the valve opening 170.Since the valve opening 170 of the valve film 17 is contacted with andclosed by the raised structure 167, the gas in the second outlet chamber184 will not be reversely returned to the first outlet chamber 166.Consequently, the efficacy of avoiding gas leakage is enhanced.Moreover, since the gas in the second outlet chamber 184 is transferredto the second pressure-releasing chamber 183 through the communicationchannel 185, the volume of the second pressure-releasing chamber 183 isexpanded. Consequently, the valve film 17 corresponding to the secondpressure-releasing chamber 183 is also subjected to the upward curvydeformation. Since the valve film 17 is no longer in contact with thefirst end of the pressure-releasing perforation 181, thepressure-releasing perforation 181 is opened. Under this circumstance,the gas in the second pressure-releasing chamber 183 is outputtedthrough the pressure-releasing perforation 181. Consequently, thepressure of the gas is released. Similarly, due to the convex structure181 a beside the pressure-releasing perforation 181 or theposition-limiting structure 188 within the second pressure-releasingchamber 183, the flexible valve film 17 can be subjected to the upwardcurvy deformation more quickly. Consequently, the pressure-releasingperforation 181 can be quickly opened. After the gas-releasing operationin one direction is performed, the gas within inner space of the targetequipment is partially or completely exited to the surrounding. Underthis circumstance, the gas pressure of the target equipment is reduced.

FIGS. 7A to 7E schematically illustrate the gas-collecting actions ofthe miniature pneumatic device of FIG. 2A. Please refer to FIGS. 1A, 2Aand 7A to 7E. As shown in FIG. 7A, the miniature pneumatic device 1comprises the miniature fluid control device 1A and the miniature valvedevice 1B. As mentioned above, the gas inlet plate 11, the resonanceplate 12, the piezoelectric actuator 13, the first insulation plate 141,the conducting plate 15, the second insulation plate 142 and the gascollecting plate 16 of the miniature fluid control device 1A are stackedon each other sequentially. There is a gap g0 between the resonanceplate 12 and the piezoelectric actuator 13. Moreover, the first chamber121 is formed between the resonance plate 12 and the piezoelectricactuator 13. The valve film 17 and the gas outlet plate 18 of theminiature valve device 1B are stacked on each other and disposed underthe gas collecting plate 16 of the miniature fluid control device 1A.The gas-collecting chamber 162 is arranged between the gas collectingplate 16 and the piezoelectric actuator 13. The first pressure-releasingchamber 165 and the first outlet chamber 166 are formed in the secondsurface 161 of the gas collecting plate 16. The secondpressure-releasing chamber 183 and the second outlet chamber 184 areconcavely formed in the first surface 180 of the gas outlet plate 18. Inan embodiment, the operating voltage of the miniature pneumatic device 1is in the range between ±10V and ±16V. Moreover, due to the arrangementsof the plural pressure chambers, the actuation of the piezoelectricactuator 13 and the vibration of the plate 12 and the valve film 17, thegas can be transferred downwardly.

As shown in FIG. 7B, the piezoelectric actuator 13 of the miniaturefluid control device 1A is vibrated downwardly in response to theapplied voltage. Consequently, the gas is fed into the miniature fluidcontrol device 1A through the at least one inlet 110 of the gas inletplate 11 from the input side. The gas is sequentially converged to thecentral cavity 111 through the at least one convergence channel 112 ofthe gas inlet plate 11, transferred through the central aperture 120 ofthe resonance plate 12, and introduced downwardly into the first chamber121.

As the piezoelectric actuator 13 is actuated, the resonance of theresonance plate 12 occurs. Consequently, the resonance plate 12 is alsovibrated along the vertical direction in the reciprocating manner. Asshown in FIG. 7C, the resonance plate 12 is vibrated downwardly andcontacted with the bulge 130 c of the suspension plate 130 of thepiezoelectric actuator 13. Due to the deformation of the resonance plate12, the volume of the chamber corresponding to the central cavity 111 ofthe gas inlet plate 11 is expanded but the volume of the first chamber121 is shrunken. Under this circumstance, the gas is pushed towardperipheral regions of the first chamber 121. Consequently, the gas istransferred downwardly through the vacant space 135 of the piezoelectricactuator 13. Then, the gas is transferred to the gas-collecting chamber162 between the miniature fluid control device 1A and the miniaturevalve device 1B. After that, the gas is transferred downwardly to thefirst pressure-releasing chamber 165 and the first outlet chamber 166through the first perforation 163 and the second perforation 164, whichare in communication with the gas-collecting chamber 162. Consequently,when the resonance plate 12 is vibrated along the vertical direction inthe reciprocating manner, the gap g0 between the resonance plate 12 andthe piezoelectric actuator 13 is helpful to increase the amplitude ofthe resonance plate 12. That is, due to the gap g0 between the resonanceplate 12 and the piezoelectric actuator 13, the amplitude of theresonance plate 12 is increased when the resonance occurs.

As shown in FIG. 7D, the resonance plate 12 of the miniature fluidcontrol device 1A is returned to its original position, and thepiezoelectric actuator 13 is vibrated upwardly in response to theapplied voltage. The difference x between the gap g0 and the vibrationdisplacement d of the piezoelectric actuator 13 is given by a formula:x=g0−d. A series of tests about the maximum output pressure of theminiature pneumatic device 1 corresponding to different values of x areperformed. The operating voltage of the miniature pneumatic device 1 isin the range between ±10V and ±16V. In case that x=1 μm˜5 μm, themaximum output pressure of the miniature pneumatic device 1 is at least300 mmHg. Consequently, the volume of the first chamber 121 is alsoshrunken, and the gas is continuously pushed toward peripheral regionsof the first chamber 121. Moreover, the gas is continuously transferredto the gas-collecting chamber 162, the first pressure-releasing chamber165 and the first outlet chamber 166 through the vacant space 135 of thepiezoelectric actuator 13. Consequently, the pressure in the firstpressure-releasing chamber 165 and the first outlet chamber 166 will begradually increased. In response to the increased gas pressure, theflexible valve film 17 is subjected to the downward curvy deformation.Consequently, the valve film 17 corresponding to the secondpressure-releasing chamber 183 is moved downwardly and contacted withthe convex structure 181 a corresponding to the first end of thepressure-releasing perforation 181. Under this circumstance, thepressure-releasing perforation 181 of the gas outlet plate 18 is closed.In the second outlet chamber 184, the valve opening 170 of the valvefilm 17 corresponding to the outlet perforation 182 is openeddownwardly. Then, the gas within the second outlet chamber 184 istransferred downwardly to the outlet structure 19 through the outletperforation 182 and then transferred to the inner space of the targetequipment which is in communication with the outlet structure 19.Consequently, the inner space of the target equipment is pressurized,and the purpose of collecting the gas pressure is achieved.

Then, as shown in FIG. 7E, the resonance plate 12 of the miniature fluidcontrol device 1A is vibrated upwardly. Under this circumstance, the gasin the central cavity 111 of the gas inlet plate 11 is transferred tothe first chamber 121 through the central aperture 120 of the resonanceplate 12, and then the gas is transferred downwardly to the miniaturevalve device 1B through the vacant space 135 of the piezoelectricactuator 13. As the gas pressure is continuously increased along thedownward direction, the gas is continuously transferred to thegas-collecting chamber 162, the second perforation 164, the first outletchamber 166, the second outlet chamber 184 and the outlet perforation182 and then transferred to the target equipment which is incommunication with the outlet structure 19. Such pressure-collectingoperation may be but not limited to be triggered by the pressuredifference between the ambient pressure of the input side and the gaspressure of the inner space of the target equipment.

FIG. 8 schematically illustrate the gas-releasing actions or thepressure-reducing actions of the miniature pneumatic device of FIG. 1A.In case that the inner pressure of the target equipment is greater thanthe ambient air pressure of the input side, the gas-releasing operation(or a pressure-reducing operation) may be performed. As mentioned above,the user may adjust the amount of the gas to be fed into the miniaturefluid control device 1A, so that the gas is no longer transferred to thegas-collecting chamber 162. Under this circumstance, the gas istransferred from the outlet structure 19 to the second outlet chamber184 through the outlet perforation 182. Consequently, the volume of thesecond outlet chamber 184 is expanded, and the flexible valve film 17corresponding to the second outlet chamber 184 is bent upwardly. Inaddition, the valve film 17 is in close contact with the raisedstructure 167 corresponding to the first outlet chamber 166. Since thevalve opening 170 of the valve film 17 is closed by the raised structure167, the gas in the second outlet chamber 184 will not be reverselyreturned to the first outlet chamber 166. Moreover, the gas in thesecond outlet chamber 184 is transferred to the secondpressure-releasing chamber 183 through the communication channel 185,and then the gas in the second pressure-releasing chamber 183 istransferred to the pressure-releasing perforation 181. Under thiscircumstance, the gas-releasing operation is performed. After thegas-releasing operation of the miniature valve device 1B in onedirection is performed, the gas within the inner space of the targetequipment is partially or completely exited to the surrounding. Underthis circumstance, the inner pressure of the equipment is reduced.

The performance data of the miniature pneumatic device 1 with differentsizes of square suspension plates 130 are listed in Table 3.

TABLE 3 Side length of square suspension plate 2 mm 2.5 mm 3.5 mm 4 mm4.5 mm 5 mm Defect rate 1/20 = 1/20 = 2/20 = 3/20 = 3/20 = 5/20 = 5% 5%10% 15% 15% 25%

The results of the above table are obtained by testing 20 random samplesof the miniature pneumatic device 1 with each different size of squaresuspension plates 130. When the side length of the square suspensionplate 130 is in the range between 2.5 mm and 3.5 mm, the maximum outputpressure of the miniature pneumatic device 1 can reach over 300 mmHg,and the defect rate is reduced. The reason of reduction of defect rateis supposed to be that smaller size brings greater rigidity of thesuspension plate 130. With greater rigidity, horizontal deformation ofthe suspension plate 130 is reduced when it is vibrating vertically, andthe vibration of the piezoelectric actuator 13 can be steady in thefixed direction during operation. Thus, the collision interferencebetween the suspension plate 130 and the resonance plate 12 or othercomponents can be reduced, and a specified distance between thesuspension plate 130 and the resonance plate 12 is maintained thatreducing the noise. Hence, the results of the quality tests of the finalproducts show that the number of the unqualified product is obviouslyreduced. In other words, the quality performance of the product isenhanced. Moreover, as the size of the suspension plate 130 is reduced,the size of the piezoelectric actuator 13 can be correspondingly made insmaller size. Under this circumstance, the volume of the gas channel isreduced and the efficacy of pushing or compressing the gas is increased.Consequently, the miniature pneumatic device 1 of the present inventionhas enhanced performance and smaller size. By contrast, in case that thesuspension plate 130 and the piezoelectric ceramic plate 133 of thepiezoelectric actuator are larger, the suspension plate 130 is readilysuffered from distortion during vibration because the rigidity of thesuspension plate 130 is deteriorated. If the distortion of thesuspension plate 130 occurs, the collision interference between thesuspension plate 130 and the resonance plate 12 or other components iseasily happened and thus the noise is generated. The noise problem mayresult in the defective product. That is, as the sizes of the suspensionplate 130 and the size of the piezoelectric ceramic plate 133 areincreased, the defect rate of the miniature pneumatic device 1 isincreased. By reducing the size of the suspension plate 130 and the sizeof the piezoelectric ceramic plate 133, the performance of the miniaturepneumatic device 1 is increased, the noise is reduced, and the defectrate is reduced.

The fact that the size reduction of the suspension plate 130 increasesthe performance and maximum output pressure is realized according to theresults of experiments rather than theoretical mathematic formulae.

After the miniature fluid control device 1A and the miniature valvedevice 1B are combined together, the total thickness of the miniaturepneumatic device 1 is in the range between 1.5 mm and 4 mm. Since theminiature pneumatic device is slim and portable, the miniature pneumaticdevice is suitably applied to medical equipment or any other appropriateequipment.

From the above descriptions, the present invention provides theminiature pneumatic device. The miniature pneumatic device comprises theminiature fluid control device and the miniature valve device. After thegas is fed into the miniature fluid control device through the inlet,the piezoelectric actuator is actuated. Consequently, a pressuregradient is generated in the fluid channels of the miniature fluidcontrol device and the gas-collecting chamber to facilitate the gas toflow to the miniature valve device at a high speed. Moreover, due to theone-way valve film of the miniature valve device, the gas is transferredin one direction. Consequently, the pressure of the gas is accumulatedto any equipment that is connected with the outlet structure, which isreferred as the target equipment above. For performing a gas-releasingoperation (or a pressure-reducing operation), the user may adjust theamount of the gas to be fed into the miniature fluid control device, sothat the gas is no longer transferred to the gas-collecting chamber.Under this circumstance, the gas is transferred from the outletstructure to the second outlet chamber of the miniature valve device,then transferred to the second pressure-releasing chamber through thecommunication channel, and finally exited from the pressure-releasingperforation. By the miniature pneumatic device of the present invention,the gas can be quickly transferred while achieving silent efficacy.Moreover, due to the special configurations, the miniature pneumaticdevice of the present invention has small volume and small thickness.Consequently, the miniature pneumatic device is portable and suitable tobe applied to medical equipment or any other appropriate equipment. Inother words, the miniature pneumatic device of the present invention hassignificant advantages that creating industrial values.

While the invention has been described in terms of what is presentlyconsidered to be the most practical and preferred embodiments, it is tobe understood that the invention needs not be limited to the disclosedembodiment. On the contrary, it is intended to cover variousmodifications and similar arrangements included within the spirit andscope of the appended claims which are to be accorded with the broadestinterpretation so as to encompass all such modifications and similarstructures.

What is claimed is:
 1. A miniature pneumatic device, comprising: a miniature fluid control device comprising: a gas inlet plate; a resonance plate having a central aperture; a piezoelectric actuator; and a gas collecting plate, wherein a length of the gas collecting plate is in a range between 4 mm and 10 mm, a width of the gas collecting plate is in a range between 4 mm and 10 mm, and a length/width ratio of the gas collecting plate is in a range between 0.4 and 2.5, wherein the gas inlet plate, the resonance plate, the piezoelectric actuator and the gas collecting plate are stacked on each other sequentially, and a gap is formed between the resonance plate and the piezoelectric actuator to define a first chamber, wherein when the piezoelectric actuator is actuated, a gas is fed into the miniature fluid control device through the gas inlet plate, transferred through the resonance plate, introduced into the first chamber, and further transferred; and a miniature valve device comprising a valve film and a gas outlet plate, wherein the gas collecting plate, the valve film and the gas outlet plate are combined together, the valve film has a valve opening, and a length and a width of the gas outlet plate are identical to those of the gas collecting plate, wherein after the gas is transferred from the miniature fluid control device to the miniature valve device, a pressure-collecting operation or a pressure-releasing operation is selectively performed.
 2. The miniature pneumatic device according to claim 1, wherein the length of the gas collecting plate is in a range between 6 mm and 8 mm, the width of the gas collecting plate is in a range between 6 mm and 8 mm, and a length/width ratio of the gas collecting plate is in a range between 0.75 and 1.33.
 3. The miniature pneumatic device according to claim 1, wherein the length of the gas collecting plate is 6 mm, and the width of the gas collecting plate is 6 mm.
 4. The miniature pneumatic device according to claim 1, wherein the gas inlet plate comprises at least one inlet, at least one convergence channel and a central cavity, and a convergence chamber is defined by the central cavity, wherein after the gas is introduced into the at least one convergence channel through the at least one inlet, the gas is guided by the at least one convergence channel and converged to the convergence chamber, wherein the convergence chamber is aligned with the central aperture of the resonance plate.
 5. The miniature pneumatic device according to claim 1, wherein the piezoelectric actuator comprises: a suspension plate having a square shape, wherein the suspension plate is permitted to undergo a curvy vibration from a middle portion to a periphery portion of the suspension plate; an outer frame arranged around the suspension plate; at least one bracket connected between the suspension plate and the outer frame for elastically supporting the suspension plate; and a piezoelectric ceramic plate having a square shape, wherein a length of the piezoelectric ceramic plate is equal to or less than a length of the suspension plate, and the piezoelectric ceramic plate is attached on a first surface of the suspension plate, wherein when a voltage is applied to the piezoelectric ceramic plate, the suspension plate is driven to undergo the curvy vibration.
 6. The miniature pneumatic device according to claim 5, wherein the suspension plate has a square shape.
 7. The miniature pneumatic device according to claim 1, wherein the gas collecting plate comprises a first perforation, a second perforation, a first pressure-releasing chamber, a first outlet chamber and a fiducial surface, wherein the gas collecting plate further comprises a raised structure disposed in the first outlet chamber and located at a level higher than the fiducial surface of the gas collecting plate, the first perforation is in communication with the first pressure-releasing chamber, and the second perforation is in communication with the first outlet chamber.
 8. The miniature pneumatic device according to claim 7, wherein the gas outlet plate comprising a pressure-releasing perforation, an outlet perforation, a second pressure-releasing chamber, a second outlet chamber, at least one position-limiting structure and a fiducial surface, wherein the second pressure-releasing chamber and the second outlet chamber are concavely formed in the fiducial surface of the gas outlet plate, the pressure-releasing perforation is located at a center of the second pressure-releasing chamber, a convex structure is located beside an end of the pressure-releasing perforation, the convex structure is located at a level higher than the fiducial surface of the gas outlet plate, the outlet perforation is in communication with the second outlet chamber, the at least one position-limiting structure is disposed within the second pressure-releasing chamber, and the gas outlet plate further comprises a communication channel between the second pressure-releasing chamber and the second outlet chamber, wherein the gas collecting plate, the valve film and the gas outlet plate are combined together, the pressure-releasing perforation of the gas outlet plate is aligned with the first perforation of the gas collecting plate, the second pressure-releasing chamber of the gas outlet plate is aligned with the first pressure-releasing chamber of the gas collecting plate, and the second outlet chamber of the gas outlet plate is aligned with the first outlet chamber of the gas collecting plate, wherein the valve film is arranged between the gas collecting plate and the gas outlet plate for blocking communication between the first pressure-releasing chamber and the second pressure-releasing chamber.
 9. The miniature pneumatic device according to claim 8, wherein after the gas is downwardly transferred from the miniature fluid control device to the miniature valve device, the gas is introduced into the first pressure-releasing chamber and the first outlet chamber through the first perforation and the second perforation, and the valve film is quickly contacted with the convex structure of the gas outlet plate to provide a pre-force to tightly close the pressure-releasing perforation, and the gas within the first outlet chamber is further transferred to the outlet perforation of the miniature valve device through the valve opening of the valve film, so that the pressure-collecting operation is performed.
 10. The miniature pneumatic device according to claim 9, wherein while the pressure-releasing operation is performed, the gas is transferred from the outlet perforation to the second outlet chamber to move the valve film, the valve opening of the valve film is contacted with and closed by the gas collecting plate, the gas is transferred from the second outlet chamber to the second pressure-releasing chamber through the communication channel, the valve film corresponding to the second pressure-releasing chamber is moved, and the gas is exited from the pressure-releasing perforation.
 11. The miniature pneumatic device according to claim 10, wherein the gas outlet plate further comprises at least one position-limiting structure, wherein the at least one position-limiting structure is disposed within the second pressure-releasing chamber, and the at least one position-limiting structure assists in supporting the valve film to avoid collapse of the valve film.
 12. The miniature pneumatic device according to claim 11, wherein a thickness of the position-limiting structure is 0.2 mm.
 13. The miniature pneumatic device according to claim 5, wherein a length of the suspension plate is in a range between 2 mm and 4.5 mm, a width of the suspension plate is in a range between 2 mm and 4.5 mm, and a thickness of the suspension plate is in a range between 0.1 mm and 0.3 mm.
 14. The miniature pneumatic device according to claim 13, wherein the length of the suspension plate is in a range between 2.5 mm and 3.5 mm, the width of the suspension plate is in a range between 2.5 mm and 3.5 mm, and the thickness of the suspension plate is 0.2 mm.
 15. The miniature pneumatic device according to claim 5, wherein a length of the piezoelectric ceramic plate is equal to or less than a length of the suspension plate, the length of the piezoelectric ceramic plate is in a range between 2 mm and 4.5 mm, a width of the piezoelectric ceramic plate is in a range between 2 mm and 4.5 mm, a thickness of the piezoelectric ceramic plate is in a range between 0.05 mm and 0.3 mm, and a length/width ratio of the piezoelectric ceramic plate is in a range between 0.44 and 2.25.
 16. The miniature pneumatic device according to claim 15, wherein the length of the piezoelectric ceramic plate is in a range between 2.5 mm and 3.5 mm, the width of the piezoelectric ceramic plate is in a range between 2.5 mm and 3.5 mm, and the thickness of the piezoelectric ceramic plate is 0.1 mm.
 17. The miniature pneumatic device according to claim 5, wherein the suspension plate further comprises a bulge, and the bulge is formed on a second surface of the suspension plate, wherein a thickness of the bulge is in a range between 0.02 mm and 0.08 mm.
 18. The miniature pneumatic device according to claim 1, wherein the miniature fluid control device further comprises at least one insulation plate and a conducting plate, wherein the at least one insulation plate and the conducting plate are stacked on each other and located under the piezoelectric actuator.
 19. The miniature pneumatic device according to claim 7, wherein a thickness of the raised structure corresponding to the first outlet chamber of the gas collecting plate is in a range between 0.1 mm and 0.55 mm.
 20. The miniature pneumatic device according to claim 1, wherein after the miniature fluid control device and the miniature valve device are combined together, a total thickness of the miniature pneumatic device is in a range between 1.5 mm and 4 mm. 